Causes of hydronephrosis in pyelonephritic children
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《美国医学杂志》
Department of Pediatric Nephrology,Amirkola Children Hospital, Babol Medical University, Iran
Urinary tract infection (UTI) is one of the most common bacterial infectious diseases among children. Since 1960, the use of radiological imaging has been accepted in child with UTI.[1] However, the choice of radiological imaging in children is controversial. Urinary tract ultrasonography is sometimes preformed for initial upper urinary tract imaging because of the absence of radiation. Radiologists may report various degrees of dilation of collecting system and recommended further investigation to detect abnormalities such as vesicoureteral reflux (VUR) or ureteroplevic junction obstruction (UPJO). VUR was reported in 30%-50% of the children with UTI[2], and dilatation of collecting system was reported in about 27%-28% of children with UTI. [3],[4]
Based on the data collected from September 1996 to April 2003, all symptomatic febrile UTI patients referred to Department of Pediatric Nephrology of Amirkola Children Hospital (north of Iran) were enroled in this study, and causes of urinary tract dilation were evaluated. UTI was confirmed with positive urine culture in the samples. Any patient with dilation of collecting system (by ultrasonography) was selected. Then, VCUG (voiding cystourethrography) was done, and if the patients do not have VUR, IVP (Intravenous pyelography) or DTPA (Diethylenetriamine pentaacetate) imaging was conducted. Statistical analysis was performed using SPSS version 10 and student t-test was used to compare the P-values, which is less than 0.05 and considered significant. 346 patients were admited in the hospital with diagnosis of UTI. 70 (20%) subjects had dilation of UTI by ultrasound. 40 (57%) patients were male, younger than the female patients (45 months vs 63 months). 29 (41%) subjects had 6-12-years-old that were more than other age-groups. Among the age-group below 2 years, the numbers of males outnumbered the females table1. 37 (53%) patients had bilateral involvement and 27 (73%) of them were males. 40 (57%) and 13 (19%) patients had VUR and UPJO respectively (p<0.05) table1. 26 (65%) with VUR had bilateral involvement and 22 (55%) of them were male. VUR was the most common cause of hydronehrosis in the patients with pyelonephritis in both sexes and all age groups, but renal stone was a second cause of hydronephrosis in males above 6 yr table1.
Ultrasonography is a non-invasive and non-ionizing radiation form of imaging which could detect dilation of collecting system. Foresman et al reported dilation of kidney in 52 (28%) patients with UTI.[3] Some authors showed the frequency of VUR had no difference between patients with or without dilatation (39% vs 32%).[5] Also, the sensitivity and specificity of ultrasound for detection of VUR were 40% and 76% respectively; positive and negative predictive value of ultrasound for VUR were 32% and 82% respectively. [4],[5] Dipietro found ultrasound is not reliable for detection of VUR in children aged 5 yr or older.[6] In this study, 20% of patients with UTI had dilation of collating system. Mean age in males was less than that of females, and 41% of patients were between 6-15 yr old. Urinary tract abnormalities are higher in young males, and this study shows more younger boys with hydronephrosis than girls. So, delay in diagnosis (especially in males) may cause irreversible renal damage.
The most common cause of dilation of collecting system in this study was VUR (57%) and than UPJO (19%). Saunders et al studied 74 children with 91 hydronephrotic kidneys evaluated with isotope scan (mercaptoacetyl tryglycin). Obstructive hydronephrosis in 22 kidneys (21 with UPJO and 1 with ureterovesical junction obstruction) and non-obstructive hydronephrosis in the 69 kidneys were diagnosed.[7]
According to this study, although VUR is the most common cause of dilation collecting system, but ultrasonography could not predict the VUR, and other causes of dilation of collecting system should be considered. Surgical or non-surgical follow-up can prevent irreversible renal damage, especially in male young children.
References
1. Smellie JM, Hodson, CJ, Edwards D, Normand IC. Clinical and radiological features of urinary infection in childhood. BKJ 1964; 2 : 1222.
2. Smellie JM, Normand JCS, Katz G. Children with urinary tract infection: a comparison of those with and without vesicoureteral reflux. Kidney Int 1981; 20 : 717-722.
3. Foresman WH, Hulbert WC, JR Rabinowitz R. Dose urinary tract ultrasonography at hospitalization for acute pyelonephritis predict vescourereteral reflux. J Urol 2001; 165 : 2232-2234.
4. Mahant S, Friedman J, Macartur C. Renal ultrasound findings and vesicoureteral reflux in children hospitalized with urinary tract infection. Arch Dis Child 2002; 86: 419-421.
5. Davey MS, Zerin JM, Reilly C et al. Mild renal dilatation is not predictive of vesicoureteral reflux in children. Pediatr Radiol 1997; 27 : 908-911.
6. Dipietro MA, Blane CE, Zerin MG. Vesicoureteral reflux in older children: concordance of us and voiding cysturethrographyic finding. Radiology 1997; 205; 821-822.
7. Saunders CA, Choong KK, Lavcos G, Farlow D, Gruenewald SM. Assessment of pediatric hydronephrosis using o output efficiency. J Nucl Med 1997; 38 (9) : 147787-147789.(Sorkhi Hadi)
Urinary tract infection (UTI) is one of the most common bacterial infectious diseases among children. Since 1960, the use of radiological imaging has been accepted in child with UTI.[1] However, the choice of radiological imaging in children is controversial. Urinary tract ultrasonography is sometimes preformed for initial upper urinary tract imaging because of the absence of radiation. Radiologists may report various degrees of dilation of collecting system and recommended further investigation to detect abnormalities such as vesicoureteral reflux (VUR) or ureteroplevic junction obstruction (UPJO). VUR was reported in 30%-50% of the children with UTI[2], and dilatation of collecting system was reported in about 27%-28% of children with UTI. [3],[4]
Based on the data collected from September 1996 to April 2003, all symptomatic febrile UTI patients referred to Department of Pediatric Nephrology of Amirkola Children Hospital (north of Iran) were enroled in this study, and causes of urinary tract dilation were evaluated. UTI was confirmed with positive urine culture in the samples. Any patient with dilation of collecting system (by ultrasonography) was selected. Then, VCUG (voiding cystourethrography) was done, and if the patients do not have VUR, IVP (Intravenous pyelography) or DTPA (Diethylenetriamine pentaacetate) imaging was conducted. Statistical analysis was performed using SPSS version 10 and student t-test was used to compare the P-values, which is less than 0.05 and considered significant. 346 patients were admited in the hospital with diagnosis of UTI. 70 (20%) subjects had dilation of UTI by ultrasound. 40 (57%) patients were male, younger than the female patients (45 months vs 63 months). 29 (41%) subjects had 6-12-years-old that were more than other age-groups. Among the age-group below 2 years, the numbers of males outnumbered the females table1. 37 (53%) patients had bilateral involvement and 27 (73%) of them were males. 40 (57%) and 13 (19%) patients had VUR and UPJO respectively (p<0.05) table1. 26 (65%) with VUR had bilateral involvement and 22 (55%) of them were male. VUR was the most common cause of hydronehrosis in the patients with pyelonephritis in both sexes and all age groups, but renal stone was a second cause of hydronephrosis in males above 6 yr table1.
Ultrasonography is a non-invasive and non-ionizing radiation form of imaging which could detect dilation of collecting system. Foresman et al reported dilation of kidney in 52 (28%) patients with UTI.[3] Some authors showed the frequency of VUR had no difference between patients with or without dilatation (39% vs 32%).[5] Also, the sensitivity and specificity of ultrasound for detection of VUR were 40% and 76% respectively; positive and negative predictive value of ultrasound for VUR were 32% and 82% respectively. [4],[5] Dipietro found ultrasound is not reliable for detection of VUR in children aged 5 yr or older.[6] In this study, 20% of patients with UTI had dilation of collating system. Mean age in males was less than that of females, and 41% of patients were between 6-15 yr old. Urinary tract abnormalities are higher in young males, and this study shows more younger boys with hydronephrosis than girls. So, delay in diagnosis (especially in males) may cause irreversible renal damage.
The most common cause of dilation of collecting system in this study was VUR (57%) and than UPJO (19%). Saunders et al studied 74 children with 91 hydronephrotic kidneys evaluated with isotope scan (mercaptoacetyl tryglycin). Obstructive hydronephrosis in 22 kidneys (21 with UPJO and 1 with ureterovesical junction obstruction) and non-obstructive hydronephrosis in the 69 kidneys were diagnosed.[7]
According to this study, although VUR is the most common cause of dilation collecting system, but ultrasonography could not predict the VUR, and other causes of dilation of collecting system should be considered. Surgical or non-surgical follow-up can prevent irreversible renal damage, especially in male young children.
References
1. Smellie JM, Hodson, CJ, Edwards D, Normand IC. Clinical and radiological features of urinary infection in childhood. BKJ 1964; 2 : 1222.
2. Smellie JM, Normand JCS, Katz G. Children with urinary tract infection: a comparison of those with and without vesicoureteral reflux. Kidney Int 1981; 20 : 717-722.
3. Foresman WH, Hulbert WC, JR Rabinowitz R. Dose urinary tract ultrasonography at hospitalization for acute pyelonephritis predict vescourereteral reflux. J Urol 2001; 165 : 2232-2234.
4. Mahant S, Friedman J, Macartur C. Renal ultrasound findings and vesicoureteral reflux in children hospitalized with urinary tract infection. Arch Dis Child 2002; 86: 419-421.
5. Davey MS, Zerin JM, Reilly C et al. Mild renal dilatation is not predictive of vesicoureteral reflux in children. Pediatr Radiol 1997; 27 : 908-911.
6. Dipietro MA, Blane CE, Zerin MG. Vesicoureteral reflux in older children: concordance of us and voiding cysturethrographyic finding. Radiology 1997; 205; 821-822.
7. Saunders CA, Choong KK, Lavcos G, Farlow D, Gruenewald SM. Assessment of pediatric hydronephrosis using o output efficiency. J Nucl Med 1997; 38 (9) : 147787-147789.(Sorkhi Hadi)